A copy of a final acetabular prosthesis designed to be used for trial reductions during hip arthroplasty to judge the correct size and position of the final acetabular prosthesis to be implanted. It is one of a set, or a set, of graduated sizes, is typically made of metal or polymer material and may be designed in the form of cages, shells, augments, or inserts. This is a reusable device intended to be sterilized prior to use.